摘要
Symbiotic nitrogen fixation between soybean and rhizobia, which directly catalyze reduction of atmospheric nitrogen into ammonia, has critical importance in agricultural economy and environment. However, soybean symbiotic nitrogen efficiency, which changes with growth stage, largely relies on symbiotic host-specificity and nodule development. In this report, symbiotic phenotypes of soybean ‘Tianlong 1’ with different inoculation (inoculated with Bradyrhizobium japonicum strain 113-2, Sinorhizobium fredii USDA205 and co-inoculated with 113-2 and USDA205) were comparatively studied at different developmental stages. Without additional nitrogen, chlorophyll content, above ground fresh weight,plant height, nodule number and nodule dry weight changed with different rhizobia at various developmental stages. 113-2 had more advantages than USDA205 in promoting plant growth and nodulation. Nodulation morphology of co-inoculation was more similar to 113-2 than USDA205. Competitive nodulation between two rhizobia promoted plant growth, which had significant agricultural application prospect. For the first time, this study provided evidence for co-inoculation with different rhizobia having positive effect on plant growth, and shed new light on the competitive relationship between different rhizobia.
